Adds variable rename maps when exporting to CDF

A new command line argument, '-m' can be used to map a
dataset,dimension,role triplet to a CDF variable name without
requiring a skeleton file.

das2/stream.c

@@ -235,7 +235,7 @@ DasErrCode DasStream_freeSubDesc(DasStream* pThis, int nPktId)
 
 PktDesc* DasStream_getPktDesc(const DasStream* pThis, int nPacketId)
 {
-	if(nPacketId < 1 || nPacketId > 99){
+	if(nPacketId < 1 || nPacketId > (MAX_PKTIDS-1)){
 		das_error(DASERR_STREAM, 
 			"Illegal Packet ID %d in getPacketDescriptor", nPacketId
 		);
@@ -245,14 +245,28 @@ PktDesc* DasStream_getPktDesc(const DasStream* pThis, int nPacketId)
 	return (pDesc == NULL)||(pDesc->type != PACKET) ? NULL : (PktDesc*)pDesc;
 }
 
+int DasStream_getPktId(DasStream* pThis, const DasDesc* pDesc)
+{
+	/* Linear search for now, but small vector assumption may no always hold
+	   in the future */
+
+	/* 0 is never a container ID */
+	for(int i = 1; i < MAX_PKTIDS; ++i){
+		if((pThis->descriptors[i] != NULL)&&(pThis->descriptors[i] == pDesc))
+			return i;
+	}
+	return -1;
+}
+
+
 DasDesc* DasStream_nextPktDesc(const DasStream* pThis, int* pPrevPktId)
 {
 	int nBeg = *pPrevPktId + 1;
 	if(nBeg < 1){
 		das_error(DASERR_STREAM, "Illegal descriptor value %d", nBeg);
 		return NULL;
 	}
-	for(int i = nBeg; i < 100; ++i){
+	for(int i = nBeg; i < MAX_PKTIDS; ++i){
 		if(pThis->descriptors[i] != NULL){
 			*pPrevPktId = i;
 			return pThis->descriptors[i];

das2/stream.h

@@ -73,10 +73,10 @@ extern "C" {
  * Desciptor IDs:
  *   The lookup ID is the same value used as the header & data IDs in the
  *   stream. The legal packet ID range depends on the stream serilazation
- *   method.  For the das2 format, the valid range is 0 to 99.
+ *   method.  For the das2 format, the valid range is 1 to 99.
  * 
- *   For the das3 format, packet ID's must be positive and fit in an integer
- *   so the maximum is about 2.1 billion. 
+ *   For the das3 format, packet ID's must be positive and fit into a 
+ *   short unsigned integer, so the valid range is 1 to 65,535.
  *
  *   Note that das v2 Streams can re-use packet ID's.  So the PacketDescriptor
  *   at, for example, ID 2 may be completely different from one invocation
@@ -452,6 +452,20 @@ DAS_API PktDesc* DasStream_getPktDesc(const DasStream* pThis, int id);
 
 #define StreamDesc_getPktDesc DasStream_getPktDesc
 
+/** If a data container is owned by this stream object, return it's packet ID
+ * 
+ * @param pThis The stream that is being asked to provide the ID
+ * 
+ * @param pDesc The owned object descriptor
+ * 
+ * @returns A number between 1 and MAX_PKTIDS, or -1 if the object is not
+ *        owned by this stream.  The returned object may be a PktDesc or 
+ *        a DasDs.
+ * 
+ * @membefof DasStream
+ */
+DAS_API int DasStream_getPktId(DasStream* pThis, const DasDesc* pDesc);
+
 
 /** Get a frame pointer by it's index
  * 

das2/util.c

@@ -544,6 +544,45 @@ bool das_assert_valid_id(const char* sId){
 	return true;
 }
 
+/* Common config-file case, remove whitespace and simple line comments */
+char* das_strip(char* sLine, char cComment)
+{
+	if(sLine == NULL) return NULL;
+
+	/* Terminate at comment char if there is one */
+	char* pBeg = sLine;
+	if(cComment != '\0'){
+		while(*pBeg != '\0'){
+			if(*pBeg == cComment){ 
+				*pBeg = '\0';
+				break; 
+			}
+			else
+				++pBeg;
+		}
+	}
+
+	/* Advance past whitespace, or bail out */
+	pBeg = sLine;
+	while(*pBeg != '\0'){
+		if(isspace(*pBeg))
+			++pBeg;
+		else	
+			break;
+	}
+	if(*pBeg == '\0')
+		return NULL;
+
+	/* Null out ending whitespace.  Loop will terminate because
+	    we know there's at least one non-space char in there */
+	char* pEnd = pBeg + strlen(pBeg) - 1;
+	while(isspace(*pEnd)){
+		*pEnd = '\0';
+		--pEnd;
+	}
+	return pBeg;
+}
+
 /* ************************************************************************* */
 /* Copy string as an XML token, leading and traily spaces are ignore,
  * internal space characters are converted and collapsed to single spaces 

das2/util.h

@@ -347,6 +347,23 @@ DAS_API void das_store_str(char** psDest, size_t* puLen, const char* sSrc);
  */
 DAS_API char* das_string(const char* fmt, ...);
 
+/** Strip whitespace from a string
+ * 
+ * @param sLine - Pointer to a writable null terminated string, or a
+ *          NULL pointer.
+ * 
+ * @param cComment - Treat the character if it was a null character
+ *          terminating the string.  Replace it with an actual null if
+ *          found. Use '\0' to avoid stripping "comments".
+ * 
+ * @returns NULL if the string consisted only of whitespace, or was empty
+ *          or was a NULL pointer. 
+ *          Otherwise a pointer to the first non-whitespace portion is 
+ *          returned.  A null character will be written to the string
+ *          at the start of trailing whitespace.
+ */
+DAS_API char* das_strip(char* sLine, char cComment);
+
 /** Copy string as an XML token
  * 
  * Copy a string ignoring leading and traily spaces.  Internal whitespace

test/ex18_waves_survey_varmap.conf

@@ -0,0 +1,34 @@
+# This file provides a mapping between Juno/Waves survey data as
+# pulled from a das2 server into desired CDF variable names.  To
+# use it run:
+#
+#  BEGIN=2020-01-01
+#  END=2020-01-02
+#
+#  SERVER="https://jupiter.physics.uiowa.edu/das/server?server=dataset"
+#  DATASET="&dataset=Juno/WAV/Survey"
+#  START="&start_time=${BEGIN}"
+#  STOP="&stop_time=${END}"
+#
+#  INPUT="${SERVER}${DATASET}${START}${STOP}"
+#  OUTPUT="./jno_wav_survey_${BEGIN}_v0.1.cdf"
+#
+#  das3_cdf -r -i "${INPUT}" -m waves_survey_cdf_map.conf -o ${OUTPUT}
+#
+
+LFR_LO       = 10 spec_dens
+LFR_LO_Epoch = 10 Time
+LFR_LO_Freq  = 10 frequency
+
+LFR_HI       = 20 spec_dens
+LFR_HI_Epoch = 20 Time
+LFR_HI_Freq  = 20 frequency
+
+HFR_LO       = 30 spec_dens
+HFR_LO_Epoch = 30 Time
+HFR_LO_Freq  = 30 frequency
+
+HFR_HI       = 40 spec_dens
+HFR_HI_Epoch = 40 Time
+HFR_HI_Freq  = 40 frequency
+